Supplement ?

Sorry for the re-post in Exercising, I just realized this forum is more appropiate!

I am about to start training again and was looking for some nutrition tips. I worked out for about 2 years before I stopped 2 months ago due to school midterms + finals. During this period I didn't eat well at well, often having only 1-2 meals per day. I lost a great deal of muscle mass but I still am overall nicely shaped. I am 19 years old male standing 6'2 at 166lbs right now ( down from 190lbs ).

Since I want to get back what I had ( I believe it will be easier to regain what I lost ) I was looking into some supplements but was afraid of over-using them. I still have some old supplies : Creatine, Glutamine, Proteins ( Myoplex ) and 110g Carb Drinks. Is mixing all of this together dangerous for my body ? If so, which ones are the most essential to a quick muscle gain ?